MEMS Sensors Still Center Stage

I recently wrote an article for EE Times titled Sensors: More Than MEMS reviewing the recent Sensors Expo in Chicago. That wasn’t meant to diss MEMS sensors, which are where the action still is as a number of sensor vendors reminded me recently. In addition to powering the Wii game console in my son’s bedroom, MEMS sensors find huge markets in consumer, automotive, networking, medical, and industrial applications. Sensors are already pervasive and on their way to being ubiquitous.

For starters take a look at your smart phone: it’s likely to contain as many as a dozen sensors, including an accelerometer, magnetometer, gyroscope, camera, GPS/A-GPS, microphone, pressure sensor, light sensor, capacitive touchscreen, and temperature sensor. And coming soon: proximity sensors so your phone can turn off the screen when you hold it to your ear or wake up when you reach for it; and MEMS-powered pico-projectors for giving impromptu presentations or vacation recaps to a group of people. Not all of these sensors are MEMS based, but many of them are. According to HIS iSuppli the MEMS sensor content in mobile devices will increase five fold in the next two years alone, with revenues for new CE and mobile MEMS devices reaching US$457.3 million in 2011.

There are numerous MEMS sensors in the average automobile, enabling airbags, electronic stability control, tire pressure monitoring, active suspension, and parking and braking systems. MEMS accelerometers are also a key part of forthcoming collision avoidance systems. Again according to iSupply, the automotive market will consume over 700 million MEMS sensors in 2011.

In his recent Digi-Key/EE Times Sensors Virtual Conference keynote, Stéphane Gervais-Ducoret, Freescale’s global marketing director for sensors, detailed some of the interesting applications that suddenly become possible when you bring enough sensors to bear.

Ducoret’s key point is that when you integrate enough different types of sensors into a device you achieve context awareness. Your cell phone might be made aware of all the relevant elements in your immediate environment, including your exact location, elevation, relative motion and direction; the temperature, humidity and noise level; your activity patterns; and your connectivity options.

Sensors can enable a wide range of localized, highly targeted services. By being able to locate you with a high degree of accuracy—thanks perhaps to a combination of GPS, cell tower and Wi-Fi triangulation—suddenly very detailed location-based services (LBS) become possible. For example, you might be on the second floor of a shopping mall and want to find a music store. Instead of searching for a directory at the far end of a long hall you query your phone, which pops up mall map and walks you to the store. Or perhaps the store puts out an ad to the phones of just those people in the mall—or even just those near the store—advertising its sale of ZZ Top posters (you pass on that one). Of course an application could quickly look you up on Facebook, determine that you were a big Rolling Stones fan, and pitch you on that poster instead. That’s when these things may be getting a bit too intrusive.

Ducoret’s larger point is that adding intelligence to MEMS devices opens up a lot of possibilities for devices and services that weren’t previously available. We used the example of context awareness in a shopping mall, but context awareness is critical in remote patient monitoring, another market where smart embedded MEMS devices are having a dramatic impact.

With silicon vendors now offering a seemingly endless stream of high precision converged sensor devices—so called sensor fusion—if you’re designing an embedded system that needs to be aware of its environment, you’re now only limited not by the silicon but by your imagination.

Think in other categories.

About John Donovan

Writer, editor, Dad
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